1. Field of the Invention
This invention relates to a method and apparatus for illuminating a display, and more particularly to a method and apparatus for externally supplying light to illuminate a transflective display within a hand-held computing device.
2. Description of Related Art
As computers and computing devices continue to be presented in ever smaller form factors, the size of displays and power supplies becomes an increasing concern. In particular, there is presently a new wave of computing devices which attempt to emulate the power of a personal computer in a form factor which can be conveniently held in one's hand, such as the "Wizard" manufactured by Sharp Corporation, and the "Zoomer" manufactured by Casio Corporation. Typically, such computing devices comprise a reflective or transflective display element, such as a liquid crystal display. A reflective display relies entirely on ambient light to allow the user to see an alphanumeric and/or graphical display. Transflective displays may be backlit by placing a light source behind the display. Backlighting a transflective display allows a user to see the display with little or no ambient light.
The problem with present backlighting schemes is that they consume relatively large amounts of power which could otherwise be used to perform computing functions. Accordingly, the user must either sacrifice (1) size and weight (i.e., the computing device must be made larger and heavier to accommodate larger power supplies), (2) visibility in low ambient light conditions, or (3) battery life.
Therefore, there is a need for an apparatus which allows a user to see images presented on a transflective display of a hand-held computing device without sacrificing battery life, or increasing the size or weight of the computing device. The present invention provides such an apparatus.